Inside-Out Approach of Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression: A Detailed Technical Description, Rationale and Outcomes

Abstract

Although lumbar stenosis was recognized as a contraindication for endoscopic spine surgery in the past, the advancement in endoscopic system design and development of approach techniques and strategies now enabled the endoscopic spine surgeons to manage all types of lumbar stenosis safely and more effectively. A full-endoscopic lumbar technique for surgical management of spinal canal stenosis is now used today in many advanced spine centers around the world as one of their standard procedures which can be done under general, regional, local anesthesia with sedation. In this technical report, we described in detail the inside-out approach of performing lumbar endoscopic unilateral laminotomy with bilateral decompression (LE-ULBD) and retrospectively reviewed hospital records of 127 patients who underwent the approach from December 2018 to March 2019 to address 1 level lumbar spinal stenosis and determined its outcome after 12-month follow-up period. Perioperative outcomes, operation time, length of hospital stay, and surgical complications were recorded and analyzed. The cross-sectional area of the thecal sac at the operated level was measured. The visual analogue scale (VAS) was assessed preoperatively, 1 month, and 12 months as well as the Oswestry Disability Index (ODI). The data were statistically analyzed (using SPSS ver. 17.0). The inside-out approach LE-ULBD was shown to effect statistically significant improvement in the VAS of leg and back pain as well as the ODI. It is a familiar, safe, and effective way of performing spinal stenosis decompression with good reproducible outcomes.

Clinical Results And Review of Techniques of Lumbar Endoscopic Unilateral Laminotomy With Bilateral Decompression (LE-ULBD) for Lumbar Stenosis

“…The concept of LEULBD is not new. Recently, Lim et al and Kim et al coined the terms, inside out (under the ligamentum flavum decompression approach) 8) and outside-in (over the top decompression) 4) approach to describe the endoscopic handling of ligamentum flavum. With the under the ligamentum flavum decompression approach focus on usage of endoscopic Kerisson Rongeurs removing the ligamentum flavum with the lamina bone together, entering the epidural space early in the procedure.…”

“…While there are differences in details, there are benefits and risks inherent to each of the various described techniques. In this technical review, we describe the key differences in the over the top decompression and under the ligamentum flavum decompression approach of LEULBD, which recently coined as Outside-in by Kim et al 4) and Inside-out by Lim et al 8) A retrospective analysis of clinical outcome of our cohort of LEULBD patient was performed.…”

Lumbar Spinal Stenosis: Ipsilateral Facet-sparing Unilateral Laminotomy for Bilateral Decompression: Technical Note and Preliminary Results

“…The learning curve of mULBD is steep, the technique does not require additional sophisticated instruments, and the rate of complications does not execeed that of comparable mini-mally invasive procedures. Alternative options are a bilateral tubular approach [12,15] or an endoscopic decompression [18][19][20].…”

Recent Trends and Changes in the Endoscopic Spinal Surgery

“…Spinal endoscopic surgery using a lumbar transforaminal approach was mainly performed for lumbar disc removal. Recently, interlaminar endoscopes equipped with large diameter working channel have been developed by various companies 7) . Moreover, various spinal endoscopic surgical instruments that can pass through large diameter working channel have been developed (Figure 1A).…”

“…Moreover, various spinal endoscopic surgical instruments that can pass through large diameter working channel have been developed (Figure 1A). Various spinal endoscopic dissectors, water-proof drills, endoscopic Kerrison punch, and radio frequency probes can be used through the large diameter working channel of modified interlaminar uniportal endoscopic systems (Figure 1A), thus facilitating bone-work such as lamino-tomy, laminectomy, and facetectomy 7) . Even with a uniportal full endoscopic approach, it is possible to proceed to discectomy, decompression, and fusion through a posterior approach rather than a transforaminal approach.…”